IPAC2011 - List of Authors (Bartolini, R.)

Paper

Title

Page

First Measurements of Higher Order Optics Parameters in the LHC

2073

G. Vanbavinckhove
NIKHEF, Amsterdam, The Netherlands
M. Aiba
PSI, Villigen, Switzerland
R. Bartolini
Diamond, Oxfordshire, United Kingdom
R. Calaga, R. Miyamoto
BNL, Upton, Long Island, New York, USA
M. Giovannozzi, F. Schmidt, R. Tomás
CERN, Geneva, Switzerland
E.H. Maclean
JAI, Oxford, United Kingdom

Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these parameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed simulations are compared to the measurements together with discussions on the measurement limitations.

THPC068

CSR and THz Emission Measurements at the Diamond Light Source

3050

R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas
Diamond, Oxfordshire, United Kingdom
I.P.S. Martin
JAI, Oxford, United Kingdom

After the successful implementation of the low alpha optics at Diamond we have started a characterisation of coherent THz emission with the aim of classifying the rich phenomenology of stable and bursting emission and to devise the best operational mode for potential THz users. In conjunction with the Diamond IR beamline B22, THz spectral data were acquired simultaneously with Schottky diode signals in the mm-wave region of the spectrum. We also report the results of comparison with numerical simulations made with the aim of reproducing the measured THz emission spectra and gaining further understanding on the mechanisms of the instability.

TUPC159

Energy Measurements with Resonant Spin Depolarisation at Diamond

1404

I.P.S. Martin, M. Apollonio, R.T. Fielder, G. Rehm
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

A precise knowledge of the electron beam energy is critical for the accurate determination of many light source parameters, such as momentum compaction factor, natural chromaticity, energy stability and undulator spectra. In common with other facilities, a method of energy measurement based on resonant spin depolarisation has been developed at Diamond. In this paper we report on progress towards storage ring characterisation using this method, as well as describing the diagnostics developments that have enabled these measurements to be made.

WEOBB03

Electron Bunch Profile Diagnostics in the Few fs Regime using Coherent Smith-Purcell Radiation

1970

N. Delerue
LAL, Orsay, France
R. Bartolini, G. Doucas, K. Pattle, C. Perry, A. Reichold, R. Tovey
JAI, Oxford, United Kingdom

Funding: John Fell Fund, University of Oxford
The rapid developments in the field of laser-driven particle acceleration hold the prospect of intense, highly relativistic electron bunches that are only a few fs long. The determination of the temporal profile of such a bunch presents new challenges. The use of a radiative process such as Smith-Purcell radiation (SPR), whereby the beam is made to radiate a small amount of e/m radiation and the temporal profile is then reconstructed from the measured spectral distribution of the radiation, is particularly promising in this respect. We summarize the advantages of SPR and present the design parameters of a forthcoming experiment at the FACET facility at SLAC with bunch lengths of the order of 60fs rms. We also discuss a new approach to the problem of the recovery of the ‘missing phase’, which is essential for the accurate reconstruction of the bunch profile.

Slides WEOBB03 [4.627 MB]

WEPC013

Tests for Low Vertical Emittance at Diamond using LET Algorithm

2031

S.M. Liuzzo, M.E. Biagini, P. Raimondi
INFN/LNF, Frascati (Roma), Italy
R. Bartolini
JAI, Oxford, United Kingdom

We present measurements recently performed at the Diamond Light Source, aimed at the achievement of low vertical emittance using the Low Emittance Tuning (LET) algorithm developed for a SuperB factory project presently in progress. The tests have been focused on the comparison between this method and the LOCO algorithm currently used at Diamond. Beam position monitor tilts estimate and multiple coupling response matrices have been introduced in the algorithm in order to optimize the procedure. After few iterations using vertical correctors and skew quadrupoles, very low vertical dispersion and emittance coupling, comparable to those obtained by LOCO, have been measured.

WEPC042

Implementation of Double Mini-beta Optics at the Diamond Light Source

2103

B. Singh, R.T. Fielder, I.P.S. Martin, G. Rehm
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Funding: Diamond Light Source Ltd.
We report the results of the implementation of two vertical mini-beta and horizontally focusing optics at the Diamond light source, the first in August 2010 and the second in March 2011. Commissioning results of the two optics changes and experimental characterization of the optics are compared with the expected performance and theoretical modeling. The implications of a possible third customized optics are also investigated.

WEPC078

Non-linear Chromaticity Studies of the LHC at Injection

2199

E.H. Maclean, M. Giovannozzi, F. Schmidt, R.J. Steinhagen, E. Todesco, R. Tomás, G. Vanbavinckhove
CERN, Geneva, Switzerland
R. Bartolini
JAI, Oxford, United Kingdom

The non-linear chromaticity of the LHC has been studied. Measurements of variation in tune with dp/p on both beams at injection optics are being compared with Q'' and Q''' as calculated with the LHC effective model. This model uses the best currently available measurements of magnetic field harmonics. An attempt is being made to optimize the b4 and b5 pool-pieces corrections in view of the corresponding chromaticity terms.

THPC071

Study of the Possibility of Implementing a Superbend in the Diamond Light Source

3059

R.P. Walker, N.P. Hammond, J. Kay, S.P. Mhaskar, B. Singh
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

We report on recent studies of the feasibility and impact of replacing one of the regular 1.4 T bending magnets in Diamond with a normal conducting 3 T "Superbend" in order to enhance the hard X-ray output for a possible future beamline. We describe the preliminary magnet design, the engineering implications and the effect on beam dynamics, including the additional constraints that arise from implementing a superbend in a DBA lattice, as compared to the more common application in a TBA lattice.

Paper	Title	Page
WEPC032	First Measurements of Higher Order Optics Parameters in the LHC	2073
	G. Vanbavinckhove NIKHEF, Amsterdam, The Netherlands M. Aiba PSI, Villigen, Switzerland R. Bartolini Diamond, Oxfordshire, United Kingdom R. Calaga, R. Miyamoto BNL, Upton, Long Island, New York, USA M. Giovannozzi, F. Schmidt, R. Tomás CERN, Geneva, Switzerland E.H. Maclean JAI, Oxford, United Kingdom
	Higher order effects can play an important role in the performance of the LHC. Lack of knowledge of these parameters can increase the tune footprint and compromise the beam lifetime. First measurements of these parameters at injection and flattop have been conducted. Detailed simulations are compared to the measurements together with discussions on the measurement limitations.

THPC068	CSR and THz Emission Measurements at the Diamond Light Source	3050
	R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas Diamond, Oxfordshire, United Kingdom I.P.S. Martin JAI, Oxford, United Kingdom
	After the successful implementation of the low alpha optics at Diamond we have started a characterisation of coherent THz emission with the aim of classifying the rich phenomenology of stable and bursting emission and to devise the best operational mode for potential THz users. In conjunction with the Diamond IR beamline B22, THz spectral data were acquired simultaneously with Schottky diode signals in the mm-wave region of the spectrum. We also report the results of comparison with numerical simulations made with the aim of reproducing the measured THz emission spectra and gaining further understanding on the mechanisms of the instability.

TUPC159	Energy Measurements with Resonant Spin Depolarisation at Diamond	1404
	I.P.S. Martin, M. Apollonio, R.T. Fielder, G. Rehm Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	A precise knowledge of the electron beam energy is critical for the accurate determination of many light source parameters, such as momentum compaction factor, natural chromaticity, energy stability and undulator spectra. In common with other facilities, a method of energy measurement based on resonant spin depolarisation has been developed at Diamond. In this paper we report on progress towards storage ring characterisation using this method, as well as describing the diagnostics developments that have enabled these measurements to be made.

WEOBB03	Electron Bunch Profile Diagnostics in the Few fs Regime using Coherent Smith-Purcell Radiation	1970
	N. Delerue LAL, Orsay, France R. Bartolini, G. Doucas, K. Pattle, C. Perry, A. Reichold, R. Tovey JAI, Oxford, United Kingdom
	Funding: John Fell Fund, University of Oxford The rapid developments in the field of laser-driven particle acceleration hold the prospect of intense, highly relativistic electron bunches that are only a few fs long. The determination of the temporal profile of such a bunch presents new challenges. The use of a radiative process such as Smith-Purcell radiation (SPR), whereby the beam is made to radiate a small amount of e/m radiation and the temporal profile is then reconstructed from the measured spectral distribution of the radiation, is particularly promising in this respect. We summarize the advantages of SPR and present the design parameters of a forthcoming experiment at the FACET facility at SLAC with bunch lengths of the order of 60fs rms. We also discuss a new approach to the problem of the recovery of the ‘missing phase’, which is essential for the accurate reconstruction of the bunch profile.
	Slides WEOBB03 [4.627 MB]

WEPC013	Tests for Low Vertical Emittance at Diamond using LET Algorithm	2031
	S.M. Liuzzo, M.E. Biagini, P. Raimondi INFN/LNF, Frascati (Roma), Italy R. Bartolini JAI, Oxford, United Kingdom
	We present measurements recently performed at the Diamond Light Source, aimed at the achievement of low vertical emittance using the Low Emittance Tuning (LET) algorithm developed for a SuperB factory project presently in progress. The tests have been focused on the comparison between this method and the LOCO algorithm currently used at Diamond. Beam position monitor tilts estimate and multiple coupling response matrices have been introduced in the algorithm in order to optimize the procedure. After few iterations using vertical correctors and skew quadrupoles, very low vertical dispersion and emittance coupling, comparable to those obtained by LOCO, have been measured.

WEPC042	Implementation of Double Mini-beta Optics at the Diamond Light Source	2103
	B. Singh, R.T. Fielder, I.P.S. Martin, G. Rehm Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Funding: Diamond Light Source Ltd. We report the results of the implementation of two vertical mini-beta and horizontally focusing optics at the Diamond light source, the first in August 2010 and the second in March 2011. Commissioning results of the two optics changes and experimental characterization of the optics are compared with the expected performance and theoretical modeling. The implications of a possible third customized optics are also investigated.

WEPC078	Non-linear Chromaticity Studies of the LHC at Injection	2199
	E.H. Maclean, M. Giovannozzi, F. Schmidt, R.J. Steinhagen, E. Todesco, R. Tomás, G. Vanbavinckhove CERN, Geneva, Switzerland R. Bartolini JAI, Oxford, United Kingdom
	The non-linear chromaticity of the LHC has been studied. Measurements of variation in tune with dp/p on both beams at injection optics are being compared with Q'' and Q''' as calculated with the LHC effective model. This model uses the best currently available measurements of magnetic field harmonics. An attempt is being made to optimize the b4 and b5 pool-pieces corrections in view of the corresponding chromaticity terms.

THPC071	Study of the Possibility of Implementing a Superbend in the Diamond Light Source	3059
	R.P. Walker, N.P. Hammond, J. Kay, S.P. Mhaskar, B. Singh Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	We report on recent studies of the feasibility and impact of replacing one of the regular 1.4 T bending magnets in Diamond with a normal conducting 3 T "Superbend" in order to enhance the hard X-ray output for a possible future beamline. We describe the preliminary magnet design, the engineering implications and the effect on beam dynamics, including the additional constraints that arise from implementing a superbend in a DBA lattice, as compared to the more common application in a TBA lattice.